Musician son here. Only suit…a well fitted and tailored black suit.
To the OP…you might want to throw in a pair of dress shoes, socks, belt, a couple of shirts and ties with the suit. I’ve seen some pretty nice suits with some pretty awful shoes and belts and shirts…and ties.
Second the vote for Nordstrom. Check the Rack first…you can always take the suit to Nordies for alterations and pay for them.
“I guess one advantage of a navy suit is that the jacket can be worn to create the “blue blazer” look when paired with khakis for a slightly businessy business casual occasion. Again, this is for the East Coast. Here, that would be “dressy.””
In a pinch you could repurpose a navy suit jacket that way, but a blazer actually is different. The archetypal blue blazer worn with khakis has brass buttons and is cut differently. It’s also a slightly lighter navy.
S has one black suit which he had custom made in LA. It fits him perfectly – he lives in DC area. He also has a navy suit that H bought when he was S’s age and it fits very well also.
OP here. You are all so helpful! I knew I could count in the folks in the CC parent cafe! If more info helps, he’s a jazz musician, and plans to stay in New Orleans to work as a musician this next year. I think he may want a black suit for gigs. He is short. and has a muscular build, if that helps. Thus far, it sounds like his best bet may be to start at J Crew and move on to Nordstrom if we don’t find anything there. Also, we’ll definitely plan to accessorize him.
Ack - that trim fit $2500 link blew my mind… have not seen “high water” pants in a long time 
Think about it would make sense to get 2 pairs of pants. That’s what my Dad used to do when he bought suits because the pants seemed to wear out more.
A few years ago we decided to get a suit for DS. We thought he might need it for interviewing… he did not, but he has one now if he ever needs it for wedding. We first tried Kohl’s, where everything looked dumpy. Then we went to Gentlemen’s Warehouse. Wow - the grey suit looked really nice on him, especially after the tailoring. We did the buy one / get one deal in combo with a blue blazer. He’ll probably get more use out of the blazer.
To me, a “good” suit needs to be fully canvassed in order to last a long time. Fused fabric (Hugo Boss, most of Men’s Wearhouse) keeps prices down but folds funny when you move and will bubble over time. Half canvassed is a good compromise; you would have to get really lucky to find a sub-$1000 fully canvassed suit.
How short ?
If he needs an extra short it will be hard to find at most traditional retailers and in most brands.
Some of this depends on what his job will be or in what settings he will mostly wear the suit, but here’s my 2cents
Good luck.
For both H and S, the shirt fit around the neck is key. Both of my guys have necks like tree trunks. Thick tree trunks.
This thread reminds me of when my parents bought me two suits and a monthly train pass as graduation presents.
The stylish young men are no longer wearing their suit jackets to the bottom on their palms; the jackets are much shorter than that. They don’t look extreme, but do look stylish and up-to-date.
Despite promoting silly, extreme styles that look like shrunken suits, Thom Browne has actually had a big influence on how modern suits have been cut over the last 10 years or so. Most younger men are wearing suits that are much tighter and shorter than before.
Kohl’s.
Great selection. Fair prices.
Dadx gives great tips for suit buying but for someone just coming out of college, 22-23ish, I think a first suit probably shouldn’t thought of as a 10-15 year investment. Sure, make sure it fits well, but most people’s physique is going to change from their early 20s. Even if one makes efforts to stay fit, many young men will still get a little broader during their 20s.
I bought S1 a navy Zegna blazer along with cream wool slacks to wear for his HS graduation a few years ago. He probably wears it at least once a week with khakis, jeans, or dressier pants. It fits beautifully, looks elegant and understated (no bright gold buttons, subtle weave, single vent). I hesitated to spend that much, but price per wear, it’s been worth it.
He does have another hand me down blue blazer that used to belong to H that he wears to parties where there’s the possibility drinks may be sloshed. About ten years ago, H and I traveled to a wedding where H was in the wedding party and was required to wear a specific blue blazer and tan slacks that he bought for the occasion. As we were getting dressed, I realized that I left the blazer at home. We made a panic trip to the only menswear store in the little resort town, and he bought an Austin Reed blazer (which, luckily, fit him pretty well). That’s now S’s party blazer.
If your son is a jazz musician, he will likely need a variety of clothing. My kid has black dress shirts, ties, suits, slacks. He also has a variety of different color shirts and ties because jazz musicians don’t always wear black.
How do they get dress shirts that are not excessively large in the chest and/or waist? Off-the-shelf dress shirts commonly have a sizing that associates the chest and waist size to the neck size. A man with a thick neck may find that dress shirts that fit his neck are too large in the chest and/or waist.
He’s about 5’6". Will it be hard to find the right fit? So confused! I’ll print out all the advice for him to look at and let him decide where to go and what to get…I’ll just provide the credit card.
He’s probably going to be a 34 or 36 Short. You might find options are more limited in those sizes.
@ucbalumnus My guys are definitely not off the rack. Every so often I drag them to a store where they can be properly measured. Neck, shoulders, chest, waist… the whole kit and kaboodle. Most stores can’t deal with their neck size and refer us to their on line store. With measurements in hand, I have more options and can shop around. S is 5’8" and 18 so his body will continue to change for a while. H is a lot more settled in his body 
Neither H nor S require/demand expensive shirts. Just ones that let them breath and don’t look like re-purposed tenting.
If he’s legit 5’6, he’ll be somewhere around 36-40 depending on how slight/stocky he is. At that height, 140 pounds will put him at around a 38(short). Under 140 likely puts him at 36. Above 147 or so puts him closer to 40.
I think you’re going to have difficulty finding the right selection. Make sure you take your time and don’t settle. I still say start at Nordstroms, although they’re probably geared for older bodies and may not have much in the shorts below size 38 or so.
My advice is for someone who works in finance or top end law or similar activity. If you’re in another area or field, take a look around at those 15 years older and heed the cues. Steve Jobs probably didn’t own a suit. :)…but what he did own fit correctly.